1. Field of Invention
The field of the currently claimed embodiments of this invention relates to optical coherence tomography (OCT) systems, and more particularly to durable single mode optical fiber probes for OCT systems and OCT systems that incorporate the probes.
2. Discussion of Related Art
Common-path (CP) interferometer based optical coherence tomography (OCT) systems can use a single mode fiber (SMF) probe to serve as both reference and sample arms [1]. This configuration allows a CP ultra-thin probe to be integrated with standard surgical instruments to provide various sensing functionalities such as force sensing or depth ranging in intra-operative settings [2]. Usually, the cleaved fiber tip provides reference light derived from Fresnel reflection; and the reference light interferes with sample light. However, a bare fiber tip without external protection can be very fragile. In addition, once the tip of a bare fiber probe is contaminated during a surgical procedure, it is very challenging to clean the fiber tip without damaging it. Another drawback of bare fiber probe in CP OCT systems is that the reference power level is not optimal to achieve high signal to noise ratio (SNR) [3, 4]. The reference power is determined by the refractive indices of glass and the media where the probe is operated. Therefore, the reference power level cannot be adjusted as in an OCT system based on a Michelson interferometer. There thus remains a need for improved probes for OCT systems, and OCT systems that incorporate the probes.